The present invention relates to the field of power generation, and more particularly to the use of distributed power generation systems to supply both real and reactive power to an electrical grid.
An electrical grid is an interconnected network for delivering electricity from suppliers to consumers. It usually consists of generating stations that produce electrical power, high-voltage transmission lines that carry power from distant sources to demand centers, and distribution lines that connect individual customers. The power provided by the grid typically includes a combination of active power (real power), measured in watts, and reactive power measured in volt-amperes reactive (“var”).
An electrical grid may contain many distributed generation sources. For example, a resident can supplement the power from the grid (“grid power”) that is provided to their residence with power generated by a residential power generation system (“local power”) installed within the residence. For example, the residential power generation system could provide 10% of the power required to the residence while the grid provides the remaining 90%. When the power generated by the residential power generation system is greater than the needs of the residence, the residential power generation system can supply power to the grid so it can be used by other residences.
A photovoltaic (PV) system is an example of a residential power generation system. A PV system converts sunlight directly to electricity. A PV system works any time the sun is shining, but more electricity is produced when the sunlight is more intense. A typical PV system provides only active power and is incapable of providing reactive power.